1. Field of the Invention
The subject invention relates to three level power inverter/converter topologies, and more particularly, to the application of synchronous rectification in a uni-directional active rectifier circuit to reduce static losses by lowering the voltage drop across the circuit utilizing power semiconductor devices.
2. Description of Related Art
Synchronous rectification is a concept that has been applied in the past, particularly in DC-DC converters at low output voltage levels. In those converters where conventional circuit topologies were utilized, a voltage drop of 0.4 V to about 1.0 V in the output rectifier is common and would be converted into a significant loss, since the output voltage of a typical DC-DC power converter is usually only about 1.0 or 2.0 V.
Synchronous rectification involves the use of a power FET connected in parallel with a diode, wherein the FET is configured to be turned on when the diode is conducting, so that current flow is re-directed through the FET. Since the FET operates with lower resistance than the diode, the voltage drop across the circuit will be lower and more efficient.
Given the efficiencies associated with synchronous rectification, it would be beneficial to apply this principle to a full power circuit of a uni-directional active rectifier, also known as a Vienna Rectifier, in order to reduce the static losses across the circuit. This would be particularly advantageous in power inverter/converter topologies employed in aerospace applications, where switching speed and efficiency are sought after.